Lycopene induces bone marrow lymphopoiesis and differentiation of peritoneal IgA-producing cells

Lycopene is a hydrocarbon-carotenoid commonly found in red fruits intake with major function correlated to antioxidative capacity in several pathological conditions, including cancer and cardiovascular diseases. Recently, lycopene has been associated with hematopoiesis, although the effects on B lymphocyte differentiation and antibody production are poorly understood. In this work, the principal aim was to investigate whether lycopene affects B lymphopoiesis and terminal differentiation into plasma cells. Distinct in vivo and in vitro strategies based on lycopene supplementation were used direct in Balb/c mice or in culture systems with cells derived of these mice. In the bone marrow, lycopene expanded B220(+)IgM(-) progenitor B cells and B220(+)IgM(+) immature B lymphocytes. In the spleen, lycopene induced terminal CD138(+) plasma cell generation. In the blood, we found prominent IgA and low IgM levels after lycopene administration. Interestingly, the pattern of peritoneal IgM(+) and IgA(+) B cells indicated a significant IgM-to-IgA class switching after lycopene injection. These data indicated that lycopene induces B cell differentiation into IgA-producing plasma cells. Thus, a new cellular function has been attributed to lycopene for B lymphocyte biology and possibly associated with humoral responses and mucosal immunity.